Electromagnetic relay utlizing a single-leaf, magnetically conductive and resilient core structure



Aprnfl 16, 1968 R. STEINER 3,378,798

ELECTROMAGNETIC RELAY UTILIZING A SINGLELEAF, MAGNETICALLY CONDUCTIVE AND RESILIENT CORE STRUCTURE Filed Oct. 20, 1965 RUDOLF ST EINVER INVENTOR.

United States Patent Ofi'ice 3,378,798 Patented Apr. 16, 1968 ELECTRUMAGNETEQ RELAY UTLEZKNG A SINGLE LEAF, MAGNETTCALLY CUN- DlUtCTlVE AND RESILHENT C(BRE STRUC- TURE Rudolf Steiner, Van Nuys, Qalil. (3624 lnglcwood Blvd, Los Angeles, (Jalii. 90016) Filled Oct. 20, 1965, Ser. No. 498,517 Claims. (Cl. 335-93) The subject of this invention is an improved electromagnetic motor utilizing various basic teachings and component parts covered in my oo-pending application Ser. No; 253,692, filing date Jan. 24, 1963, now Patent No. 3,223,861.

Conventional electromagnetic motors and, more particularly, electromagnetic relays are notorious for operation having an efiiciency equalling zero. This situation is at tributable to one characteristic that no electric power is required to retain an electromagnetic relay in the de-energized, or off position. Likewise, no work is done while holding the relay armature, together with its load contacts, in the on position by means of its energized coil. Only during the extremely short period of several milliseconds while the relay armature and contacts transfer occurs, actual work is performed by the relay coil. It is apparent that a relay coil, especially when energized with direct current, is subject to the same temperature rise and other unfavorable manifestations regardless of its operational usefulness. However, it may be less obvious, that the major portion of the useful, armature and contacts transfer period also serves purposes secondary to the electrical relay objectives. The greater part of the transfer energy is consumed for the additional loading of the armature return spring and of the, likewise, preloaded contact springs. This results in several other undesirable properties displayed by conventional, electromagnetic relays. Among those is the coil requirement for a large number of ampere-turns to initiate the parts transfer. Once the parts acceleration has become effective, a much smaller amount of coil ampere-turns would sufiice to complete the stroke. This relationship caused, among other illetfects, the rigid establishment of the so-called relay, or more appropriately, armature pick-up and drop-out values, respectively, and the extremely wide margin between these two characteristic points.

The electromagnetic motor and, especially, the electromagnetic relay in accordance with this invention is not only capable of performing in an electrically proficient manner but also within extremely close operational margins. In addition to these two improvements, it utilizes the elementary component parts of the magnetic circuit, namely, the single, continuous, magnetically conductive member taught in the referenced co-pending application, also for its electric contact opening, closing and transfer arrangements, respectively. Further advantages of the subject invention over prior art will become apparent from the following description and the accompanying drawing.

In this drawing, forming a part of this application, FIG. 1 shows, in the cross-sectional plane '11, an elevational view of a single-pole, single-throw type relay, FIG. 2 is a plan view of the same relay variety as illustrated in FIG. 1, FIG. 3 portrays in elevation and cross section, a singlepole, double-throw relay variety, FIG. 4 presents, in elevation and cross section, a coil lead connection variety, and FIG. 5 shows in a larger view, schematically, in elevation and cross section, the stationary contact arrangement within the coil of the relays in accordance with this invention.

Referring now to the drawing, wherein like reference characters designate like or corresponding parts, and particularly to FIG. 1, and, in this case encapsulated and molded electromagnetic coil 10 having a groove 12 formed in its bottom portion is mounted on a base 14, by means of, in this case, two binding screws 16, which extend, through tapped holes 17 formed in the bottom of the base 14. Two mounting holes 15 are provided in the base 14. It should be noted that several of the following details may be observed more conveniently in the, however, schematic parts illustration of FIG. 5. A single-leaf, continuous, magnetically conductive, inherently resilient and, essentially C-shaped core structure 18 is disposed, at its stationary portion 20, within said coil groove 12. Said core structure has an operational air gap 19, when not magnetized. A first electrically conductive member 22 is attached, for example, through spot welding, to the stationary portion 20 of said core structure 18 at one end 24, and to a relay terminal pin 26 at its other end 28. A tape 30 of electrically nonconductive material is mounted, at one extremity 34 on the stationary lip 32 of the core 18, extending therefrom through the coil groove 12 and positioned above said first electrically conductive member 22, terminating at a location 36 beyond thebody of the electromagnetic coil 19. A second electrically conductive member 38 is mounted on the top surface of the tape 30, originating at the stationary core lip 32 and extending therefrom through the coil groove 12 to the union with the terminal pin 40. A back stop 42 is provided, to limit the travel of the core 18; said back stop has two mounting holes 44 formed therein and it is fastened to the relay assembly by means of the same two binding screws 16 used for the installation of the coil 10 to the base 14. An insulating washer is inserted between back stop 42 and each screw 16. The two coil leads 46, 46A are brought out beyond the base and terminate in the bare stranded wires 48, 48A.

It should be noted that the total thickness of both the material used for the electrically nonconductive tape 30 and for the second electrically conductive member 38 shall be as small as practical to obtain an effective, nonferrous gap when the core lips 31 land 32 are fully attracted upon energization of the electromagnetic coil 19.

The two screws 16 are of a length so as to extend be yond the base 14, primarily to serve also as mounting screws for the subject relay to a supporting structure, obviating the use of the mounting holes 15 and of additional screws.

If the expected current-carrying capacity of the two electrically conductive members 22 and 38 requires a larger dimension for the width of each aforementioned part, the two binding screws 16 will be of an electrically nonconductive material, such as nylon, to preclude electric breakdown to the supporting structure.

The operation of the described relay construction is as follows: So long as the coil 10 is ale-energized, the relay is in the so-called normal position as shown in FIG. 1. An external load circuit connected to the terminal pins 26 and 49, respectively, will remain open. When the coil 11 is energized, by means of a circuit connected to the coil leads 48, 48A, the core 13 becomes magnetized causing the attraction of its movable lip 31 toward its stationary lip 32. This causes the closing of the electric load circuit from relay load terminal 26, through member 22, core structure 18, member 38 to the other relay load terminal 40. When the coil circuit is interrupted and the coil 10 becomes tie-energized, the movable portion of the core 18 returns by means of the inherent resilience until it engages the back stop 42. It follows that so long as the coil 10 remains energized, its magnetomotive force acts directly on the only movable element, namely, the movable portion 21 of the core structure 18. Because this magnetic construction is, in accordance with this invention and by virtue of its continuous, 'hingeless core design, like and identical with the internal electric relay load contact circuit (the latter utilizes the former), the coil 10, consequently, controls the load contacts, namely, the lip 31 and the member 38 and, therefore, the application of the required contact pressure directly, without resorting to contact springs and other auxiliary means. The combined thickness of the tape extremity 34 and of the second electrically conductive member 38 occupying the space on top of the stationary core lip 32 constitute a nonferrous obstruction against the intimate mating of lip 31 with lip 38. This arrangement, aside from being required for the performance of the relay in accordance with this invention, imparts the so-called anti-freeze feature upon the magnetic relay circuit.

The aforementioned features, especially the contactpressure generation as a direct function of the magnetomotive force created by the energized electromagnetic coil, and the anti-freeze characteristics acting also directly at the relay load-contacts result in both a new and unexpected etfect and application of the relay in accordance with the invention, namely, as a close-differential relay. In addition to this relay characteristic, which can be attained only through more complex and more expensive sensing equipment of prior art, the subject relay possesses the low ampere-turn and other operationally economical properties of the electromagnetic motor varieties described in the referenced, co-pending application. Through appropriate circuit arrangements, known in this art, the closeditferential relay can be connected so as to respond to minute variations of voltage and current, respectively, and other quantities which lend themselves for conversion into electrical manifestations.

Another, very desirable and useful relay variety, namely, a single-pole, double-throw type, may be had as illustrated in FIG. 3. To accomplish this, the back stop 42 is utilized as the back contact, also called the normally-closed contact. In this case, the back stop 42 must be of an electrically conductive material and be connected to terminal pin 50. Consequently, the normallyclosed relay load contact circuit exists between the common terminal pin 26 and the terminal pin 50', whereas the normally-open relay load contact circuit will, when closed, be established between the common terminal pin 26 and the terminal pin 49. The respective internal relay load circuit element connections are selfexplanatory from the foregoing.

It is frequently desirable to disassociate relay coil terminals from load contact terminals physically and by appearance to reduce the possibility of wiring errors. Such a modification is presented in FIG. 4, indicating this arrangement in a most economical manner through the use of the electrically conductive relay mounting screws 16 as relay coil wiring terminals. Each bare wire end 48 and 48A of the respective leads 46 and 46A is positioned under a head of one binding screw 16 and fastened by it.

The coil leads can be connected to terminal pins of the type used at locations 26, 40 and 50'. Such a method will be advantageous for the relay hookup with printedcircuit boards.

Multi-pole relays of the close-differential single-throw and double-throw variety can readily be constructed through the insertion of several core and conductor assemblies in accordance with this invention as shown in FIG. 1, within the bore of and, in this case, oblong electromagnetic coil, to respond in unison upon coil energization and de-energization, selectively.

To enhance the relay load-contact performance, a specialized surface treatment, like plating, of those mating core portions may be advantageous. Particularly the area of the core 1% adjacent to the point of engagement with the back stop 42 and the core lip 31 may require this kind of surface finish.

It is obvious that the electromagnetic motor varieties and, particularly, the close-differential relay type lend themselves for numerous applications in addition to those enumerated and described herein, utilizing one of the respective features at a time and in combination, selectively. It becomes also apparent that the herein described electromagnetic motor and the associated relay types do not preclude general-purpose applications which renders them suitable throughout an extremely wide operational range.

It is further apparent that the relay varieties, although shown in open-type configurations in the drawing, are readily suitable for installation within conventional and hermetically-sealed enclosures.

It is also understood that the electromagnetic motor and each of the relay varieties presented herein constitute but one possible embodiment of each object and that numerous modifications, variations and substitutions appear feasible without departing from the spirit of this invention.

What is claimed is:

1. An electromagnetic motor comprising: a base having at least one mounting hole formed therein, an electromagnetic coil mounted on said base, a physically continuous, metallic, inherently resilient, substantially C- shaped, magnetically conductive member having lips facing each other across a magnetically operational, variable gap and capable of reciprocating toward and away from each other, said so shaped magnetically conductive member mounted on said base with respect to said electromagnetic coil so as to form the magnetic circuit to said electromagnetic coil, a first electric circuit termination, electrically insulated from said magnetically conductive member, positioned within said gap, a second electric circuit termination connected to said resilient, magnetically conductive member, said second electric circuit termination utilizing said resilient, magnetically conductive members as an electrically conductive internal motor circuit member so as to make and break, selectively, the contact with said first electric circuit termination upon the electromagnetic coil energizing and de-energizing, respec tively.

2. An electromagnetic motor as defined in claim 1, wherein a third electric circuit termination is mounted on said base, accommodating said physically continuous, metallic, inherently resilient, substantially C-shaped, magnetically conductive member in its duty as an electrically conductive internal motor circuit member, so as to make and break and transfer, selectively, contacts with said first and with said third electric circuit termination upon the electromagnetic coil energizing and de-energizing, respectively.

3. An electromagnetically actuated device comprising: a base having at least one mounting hole and a plurality of terminal pins formed therein, an electromagnetic coil having two wire leads mounted on said base by means of at least one screw, a physically continuous, metallic, in herently resilient, substantially C-shaped, magnetically conductive member having a lip at each of its two ends facing each other across a variable, nonferrous gap; said magnetically conductive member mounted with one stationary member portion on said base with respect to said electromagnetic coil so as to dispose said lips together with said variable, nonferrous gap existing between said lips within the bore of said electromagnetic coil, a first electrically conductive member having two ends, attached, at one of its ends to said stationary portion of said magnetically conductive member and extending to and connected with its other end to a first terminal pin, an electrically nonconductive member mounted on and covering said lip of said stationary, magnetically conductive member portion and extending so as to cover said first electrically conductive member, a second electrically conductive member having two ends, mounted at one of its ends on said lip of said stationary, magnetically conduc tive member portion capable of becoming engaged with said lip of the movable portion of said magnetically conductive member upon each electromagnetic coil energization, said second electrically conductive member extending so as to cover said electrically nonconductive member to and connected with its other end to a second terminal pin, a back-stop mounted on said base so as to provide a means for the calibration of said variable, nonferrous gap and an excursion termination for the movable portion of said magnetically conductive member, selectively, upon the electromagnetic coil de-energization.

4. An electromagnetically actuated device as defined in claim 3, wherein the electromagnetic coil mounting screws are of adequate length so as to extend beyond the bottom of said base and adapted to serve as mounting screws for the entire electromagnetically actuated device.

5. An electromagnetically actuated device as defined in claim 3, wherein said back-stop is made of an electrically 15 6 conductive material and is connected with a third terminal pin so as to provide a means for the breaking and making of the contact with the movable portion of said magnetically conductive member, selectively, upon the electromagnetic coil cnergizing and de-energizing, respectively.

References Cited UNITED STATES PATENTS 12/1965 Steiner 310-31 9/1966 Hayden 335203 

1. AN ELECTROMAGNETIC MOTOR COMPRISING: A BASE HAVING AT LEAST ONE MOUNTING HOLE FORMED THEREIN, AN ELECTROMAGNETIC COIL MOUNTED ON SAID BASE, A PHYSICALLY CONTINUOUS, METALLIC, INHERENTLY RESILIENT, SUBSTANTIALLY CSHAPED, MAGNETICALLY CONDUCTIVE MEMBER HAVING LIPS FACING EACH OTHER ACROSS A MAGNETICALLY OPERATIONAL, VARIABLE GAP AND CAPABLE OF RECIPROCATING TOWARD AND AWAY FROM EACH OTHER, SAID SO SHAPED MAGNETICALLY CONDUCTIVE MEMBER MOUNTED ON SAID BASE WITH RESPECT TO SAID ELECTROMAGNETIC COIL SO AS TO FORM THE MAGNETIC CIRCUIT TO SAID ELECTROMAGNETIC COIL, A FIRST ELECTRIC CIRCUIT TERMINATION, ELECTRICALLY INSULATED FROM SAID MAGNETICALLY CONDUCTIVE MEMBER, POSITIONED WITHIN SAID GAP, A SECOND ELECTRIC CIRCUIT TERMINATION CONNECTED TO SAID RESILIENT, MAGNETICALLY CONDUCTIVE MEMBER, SAID SECOND ELECTRIC CIRCUIT TERMINATION UTILIZING SAID RESILIENT, MAGNETICALLY CONDUCTIVE MEMBERS AS AN ELECTRICALLY CONDUCTIVE INTERNAL MOTOR CIRCUIT MEMBER SO AS TO MAKE AND BREAK, SELECTIVELY, THE CONTACT WITH SAID FIRST ELECTRIC CIRCUIT TERMINATION UPON THE ELECTROMAGNETIC COIL ENERGIZING AND DE-ENERGIZING, RESPECTIVELY. 